Furnace cover lifting means

ABSTRACT

IMPROVED LIFTING APPARATUS FOR A HEATING FURNACE REMOVABLE COVER ADAPTED TO COOPERATE WITH A BASE AND FORM WITH IT A HEATING CHAMBER THROUGH WHICH A GASEOUS ATMOSPHERE IS CIRCULATED. THE LIFTING APPARATUS INCLUDES A PAIR OF LIFTING POCKETS ASSOCIATED WITH THE FURNACE COVER PERIPHERAL SIDEWALL. EACH POCKET HAS AN APERTURE WHICH EXTENDS THROUGH THE COVER SIDEWALL ADJACENT ITS TOP AND A GASTIGHT ENCLOSURE WHICH IS SECURED TO THE COVER SIDEWALL AROUND EACH APERTURE.   HOOK DEVICES ADAPTED TO BE CONNECTED TO A CRANE EACH HAVE A HOOK WHICH ENGAGES THE UPPER PERIPHERY OF A LIFTING POCKET APERTURE.

United States Patent [72] Inventor Herbert Wald Baltimore, Md. 211 Appl No. 810,275 (22] Filed Mar. 25, 1969 [45] Patented June 28,1971 [73] Assignee Bethlehem Steel Corporation [54] FURNACE COVER LlFTlNG MEANS 2 Claims, 3 Drawing Figs.

[52] US. Cl 294/67, 263/49, 294/82 [51] Int. Cl B66c 1/00 [50] Field of Search 294/67, 67 (C), 67.2, 67.3, 67.4 (A), 67.4 (C), 67.5 (A), 82, 85, 67 (DA); 263/47, 47 (A), 49, 49 (B) [56] References Cited UNITED STATES PATENTS 1,704,109 3/1929 Speck et al. 294/67.4A 1,751,905 3/1930 Button 294/82 1,918,007 7/1933 Woodruff 294/67.4B

2,547,502 4/1951 Smith et a1 294/67.4A 2,553,133 5/1951 Conner 294/82 2,708,999 5/1955 Rush 1. 294/82 3,086,807 4/1963 Russell et a1... 294/67.4A 3,138,398 6/1964 Silverman 294/67.4A 3,365,229 1/1968 Hitch et a1. 294/67 Primary Examinerl-larvey C. Hornsby Assistant Examinerl-ladd S. Lane Attorney-Joseph J. OKeefe ABSTRACT: Improved lifting apparatus for a heating furnace PATENTEnJunzslsn 3.588.168

INVENTOR flerbert We /0 FURNACE COVER LIFTING MEANS BACKGROUND OF THE INVENTION This invention relates to heating furnaces and more particularly to improved lifting apparatus for an annealing furnace innercover.

Furnaces for heat treating sheet steel in coil form generally comprise a base upon which the metal is stacked, a removable innercover which sets on the base and forms with it a heating chamber and a refractory lined outercover which is disposed over the innercover and contains burner units that provide heat for the chamber. An overhead crane with cooperating sling and hook assemblies is used to raise and lower the furnace outer and innercovers and move them to and from position on the furnace base.

Conventional innercovers are provided with lifting cars which are adapted to be engaged by standard hooks secured to crane cables when such covers are to be moved. The ears are boxlike elements having open bottoms, which receive the crane hooks, and are secured by welding to opposite sides of the outside of a cover, near its top. As is well known to those skilled in the furnace art, the cyclic operation of annealing furnaces exposes such furnace components to repeated thermal expansion and contraction. In addition the lifting ears of annealing furnace innercovers are subjected to repeated mechanical stresses each time the covers are raised and their weight is supported solely by the lifting ears. As a result of the cyclic expansion and contraction of the innercovers and the mechanical stresses set up in the innercover lifting ears the welds securing the ears to the covers experience considerable cracking. Obviously, such cracks constitute a hazard which must be remedied and a continuous program ofinspection and repair is required to maintain annealing furnace innercovers in a safe operable condition.

In addition to the aforementioned problems the location of the lifting ears on annealing furnace innercovers, ie on opposite sides of a cover near its top, necessitates the use of two men. One man is required at each lifting ear to insert a crane hook into the ear and hold the hook in place until the slack has been taken up in the cable joining the hooks to a lifting rig suspended from an overhead crane.

SUMMARY OF THE INVENTION An object of this invention is to provide improved lifting apparatus for annealing furnace innercoversv Another object of this invention is to provide an annealing furnace innercover with lifting means which are safer and require less maintenance than lifting ears on innercovers now in use.

Still another object of this invention is to provide an annealing furnace innercover with lifting means which requires only one man to secure the innercover to a crane when the cover is to be moved.

The objects of this invention are achieved by providing an annealing furnace innercover with lifting pockets which are located on opposite sides of the cover peripheral sidewall, spaced from its top. Each pocket includes an aperture in the sidewalls and each aperture is surrounded by a gastight enclo sure secured to the inside surface of the sidewall. The top of each enclosure is spaced from the upper periphery of its respective aperture and the rear portion of the enclosure is spaced from the inner surface of the innercover sidewall. A lifting device is adapted to cooperate with the lifting pockets when the cover is to be raised and moved. The lifting device includes a hook portion which engages the upper periphery of a lifting pocket aperture when the cover associated therewith is being moved. The lifting device includes a lug which extends downwardly from the hook portion of the device and engages the lower periphery of a lifting pocket aperture when the lifting device is merely positioned in the lifting pocket.

BRIEF DESCRIPTION OF 'I'H F. DRAWING FIG. 1 is an elevational view of an annealing furnace innercover equipped with the lifting apparatus olthis invention.

FIG. 2 is an enlarged side elevational view of the annealing furnace innercover of FIG. 1 showing in detail the construction of the lifting pocket and lifting device cooperatively associated therewith of this invention.

FIG. 3 is a sectional view taken along the lines 3-3 of FIG. 2v

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings there is shown in FIG. I an annealing furnace innercover 10 having peripheral sidewall 11 and top 12. The cover cooperates with its base in a gastight manner. On opposite sides of peripheral sidewall 11 and spaced from top 12 are lifting pockets l3 and 13'. Cooperatively associated with pockets l3 and 13' are lifting devices 14 and 14' respectively which are joined to lifting rig 15 by means of chains 16 and 16' respectively. Lifting rig is is secured by means of cable 17 to an overhead crane, not shown, which is used to move cover 10 in a manner well known to those skilled in the art.

Lifting pockets l3 and 13' are similar and the following description of pocket 13 is equally applicable to pocket 13'. Lifting pocket 13 includes elongated aperture 18 which is cut in sidewall 11 a distance from its top edge. Aperture 18 has top peripheral portion 19, side peripheral portions 20 and 20' and bottom peripheral portion 21. Surrounding aperture 18 on the inside of cover 10 is enclosure 22 which comprises top member 23, side members 24 and 24', bottom member 25 and inside member 26. Inside member 26 is spaced a distance A from the inside surface of peripheral sidewall 11, top member 23 is spaced a distance B from the top peripheral portion of aperture 18 and bottom member 25 is spaced a distance C from the bottom peripheral portion 21 of aperture 18 for reasons hereinafter described. Side members 24 and 24' extend between top member 23 and bottom member 25 and between lifting pocket inside member 26 and the inside surface of peripheral sidewall 11.

Lifting device 14 and 14', which cooperate with lifting pockets l3 and 13' respectively, are similar, and the following description of device 14 is equally applicable to device 14'. Lifting device 14, as shown in FIG. 3, includes shank section 27, hook section 28, base bar 29, and handle 30. Shank section 27 is elongated and has straight edge 31 which, when the lifting device is in position, abuts the outside surface of peripheral sidewall 11. The upper end of shank section 27 is enlarged and includes opening 32 through which chain 16 is secured. Hook section 28 extends outwardly from straight edge 31 of shank section 27, intermediate its ends. Hook section 28 includes horizontal sidewall engaging portion 33, upwardly extending portion 34 and bottom portion 35. Hook section sidewall engaging portion 33 has a length D which is at least equal to thickness T of peripheral sidewall 1]. Hook section upwardly extending portion 34 has edge 36 which extends upwardly from sidewall-engaging portion 33 and outwardly and away from shank section straight edge 31. Extending downwardly from hook section lower portion 35 and outwardly and away from shank section straight edge 31 is positioning lug 37. Lug 37 has lower inside edge 38 which is spaced from shank section straight edge 31 a distance E which is greater than the thickness T of peripheral sidewall 11. Base bar 29 extends perpendicularly of the bottom of shank section 27 to which it is secured by welding and acts to stabilize lifting device 14 when it is being placed in position. Handle 30 is secured to the underside of base bar 29 and is used to position the lifting device in pocket 13.

When innercover 10 is to be moved a crane positions lifting rig 15 above the cover and lifting devices 14 and 14' at opposite ends of the lifting rig are suspended in the vicinity of lifting pockets l3 and 13'. A single crane follower grasps the lower edge of handle 30 and moves lifting device 14 until it is adjacent lifting pocket 13. The crane follower then inserts hook section 28 through sidewall aperture III until lifting device shank portion straight edge 3| abuts the peripheral sidewall outer surface. Lifting device 14 is lowered and lug 37 extends down into lifting pocket 13 and the lifting device rests on the lower periphery 21 of aperture 18. Lifting device shank section 27 extends vertically with its straight edge abutting peripheral sidewall 11 and lifting device base bar 29 prevents the lifting device from slipping to the side and falling out of position. After lifting device 14 is engaged in lifting pocket 13, the crane follower moves around the innercover to lifting pocket 13' and positions lifting device 14 in the same manner.

In a specific embodiment of this invention an annealing furnace innercover 10, 9 6 inches in height, 11 4% inches in diameter, is open at the bottom and contains two 1% inches x 3% inches apertures 18 in peripheral sidewall 11 spaced 2 feet from upper end 12. Surrounding each aperture is an enclosure 22, fastened to the inner wall in a gastight manner. Said enclosure consists of top member 23 spaced 1 /2 inches from the upper periphery of aperture 18, inside member 26 spaced 1% inches from the inner surface of sidewall 11, bottom member 25 which joins the inner surface of sidewall 11 2 /2 inches below the lower periphery of aperture 18 and side members 24 and 24 located three-fourths inches from the vertical por tions of aperture 18 Lifting devices 14 and 14' consist of an 8% inches elongated shank portion 27, a rounded upper end containing a one-half inch opening 32, a three-eighths inch horizontal portion 33 located 4 inches from the lower extremity of said device and hook portion 28 extending 1% inches outwardly from elongated shank portion inside edge. A one-fourth inch X one-half inch positioning lug 37 is spaced a distance from the shank portion greater than the wall thickness of peripheral sidewall 11. Completing the lifting device is stabilizing portion 29 which is inches wide with 6 foot extension handles 30 fastened thereto.

The construction recited above shows an annealing furnace innercover raised by its own peripheral sidewall and lifting devices. No stresses are set up at weld junctures consequently weld failures, which heretofore represented a continuing problem, are eliminated.

The utilization of this device is labor saving. A single cranefollower can sequentially position each lifting device locking it in place, step out of the way and signal for the crane operator to move the innercover.

I claim:

1. In a heating furnace cover adapted to cooperate with a base in a gastight manner and having a peripheral sidewall and a top, the combination therewith of:

A. a pair oflifting pockets, each said pocket having:

i. an aperture in said peripheral sidewall spaced from the upper end thereof,

ii. enclosure means surrounding said aperture and secured to the inner surface ofsaid sidewall, said enclosure comprising:

a. a top portion spaced from the upper periphery of said aperture,

b. an inner portion spaced from the inner surface of said sidewall; and

B. lifting means adapted to extend through said aperture of each said pocket and engage the upper portion, said lifting means comprising:

i. an elongated shank portion having straight edge which abuts furnace peripheral sidewall when the lifting means is in position,

an enlarged upper end containing an opening therein;

ii. a hook portion located intermediate the ends of said elongated shank portion, said hook portion having a sidewall engaging section perpendicular to the elongated shank portion extending a distance at least equal to the thickness of the peripheral sidewall,

a hook section extending upwardly from the sidewall engaging section and outwardly from the elongated shank portion,

iii. a stabilizing portion with extension handles fastened thereto; and

iv. a lug portion.

2. In a heating furnace cover adapted to cooperate with a base in a gastight manner and having a peripheral sidewall and a top, the combination therewith of A. a pair of lifting pockets, each said pocket having:

i. an aperture in said peripheral sidewall spaced from the upper end thereof,

ii. enclosure means surrounding said aperture and secured to the inner face of said sidewall, said enclosure comprising:

a. a top portion spaced from the upper periphery of said aperture,

b. an inner portion spaced from the inner surface of said sidewall; and

B. lifting means adapted to extend through said aperture of said pocket and to engage the upper portion, said lifting means comprising:

'. an elongated shank portion having a straight edge which abuts furnace peripheral sidewall when the lifting means is in position, an enlarged upper end containing an opening therein ii. a hook portion;

iii. a stabilizing portion with extension handles fastened thereto; and

iv. a lug portion which extends downwardly from said hook portion, and outwardly and away from the elongated shank portion straight edge, and said lug portion lower inside edge is spaced from the elongated shank portion straight edge a distance greater than the thickness of the peripheral sidewall. 

